His long talk is just like 'a hundred days of sermonizing without a fart.'

He is receiving treatment for obsessive-compulsive disorder.

In mathematics, it is important to examine the parity of numbers.

This metal has very high malleability.

The sexology class is very interesting.

Sex chromosomes play an important role in determining the sex of an organism.

Sex chromosomes play a crucial role in determining the sex of an organism.

We have a responsibility to protect the biodiversity of the Earth.

Cats are digitigrade animals, they walk on their toes.

His research mainly focuses on the plantigradism of mammals.